I’ve been playing with Capistrano a lot lately and loving it. Here is an example of how easy it is to write tasks and use them on multiple remote servers.

This task installs your SSH public key on the remote machine to allow key-based authentication:

set :key_file do
  Capistrano::CLI.ui.ask "enter public key to push: "

desc "configures key-based SSH administration"
task :push_key, :roles  => :all do
  key_location = File.expand_path(key_file)
  unless File.exist?(key_location) and key_file.match(/\.pub$/)
    puts "Couldn't locate public key. Try again"
  key_file_name = File.basename(key_location)
  upload key_location, "/tmp/#{key_file_name}"
  run "if [ ! -e ~/.ssh ];then mkdir ~/.ssh; fi"
  run "cat /tmp/#{key_file_name} >> ~/.ssh/authorized_keys"
  run "rm /tmp/#{key_file_name}"
  run "chmod 600 ~/.ssh/authorized_keys"

Silky smooth.